CN111313749A - Surface-mounted piezoelectric-driven two-degree-of-freedom underwater mechanical arm and driving method thereof - Google Patents

Abstract

The invention discloses a patch type piezoelectric driving two-degree-of-freedom underwater manipulator and a driving method thereof. The manipulator comprises a plurality of unit arm sections connected in sequence and connecting components between the arm sections; The piezoelectric vibrator on the node is applied with a driving signal with a phase difference of π/2, so that each point in contact with the adjacent piezoelectric vibrator produces a slight elliptical motion, and the driving force is generated through friction, which can respectively realize the unit arm section winding and The rotation of the piezoelectric vibrator of the adjacent unit arm section and the rotation of the unit arm section around its own piezoelectric vibrator axis, and because the unit arm section and its adjacent unit arm section are orthogonal in space, the two arm sections can be realized in two directions. A two-degree-of-freedom rotation in an orthogonal plane. The invention is easy to seal and realize miniaturization, is free from electromagnetic interference, can be powered off and self-locked, does not need to adjust the modal coupling frequency consistency of different phase modes, reduces restrictions on the design, size and shape of the mechanical arm, and is suitable for underwater applications. In particular, the deep-sea micro-robot working manipulator has important application prospects.

Description

A patch type piezoelectric driven two-degree-of-freedom underwater manipulator and its driving method

technical field

The invention relates to the field of piezoelectric drives and robots, in particular to a patch-type piezoelectric drive two-degree-of-freedom underwater mechanical arm and a driving method thereof.

Background technique

The development and utilization of marine resources has always been the focus of research all over the world. One of the important modern tools is underwater robots. For cabled underwater robots, traditional hydraulic or motor-driven industrial-grade working manipulators are generally equipped. However, due to the limitation of its own size, energy and some special working environment, micro-miniature cableless autonomous underwater robots are generally not equipped with suitable working manipulators. High energy, miniaturization and subsequent waterproofing are difficult. On the other hand, tiny autonomous underwater robots have some special requirements for robotic arms, such as high pressure, low temperature, immunity from electromagnetic interference, and high control accuracy.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a patch type piezoelectric driven two-degree-of-freedom underwater manipulator and a driving method thereof in view of the defects involved in the background technology.

The present invention adopts the following technical solutions for solving the above-mentioned technical problems:

A patch-type piezoelectric-driven two-degree-of-freedom underwater manipulator includes several N+1 unit arm segments and N connecting components, where N is a natural number greater than or equal to 1, and the N+1 unit arm segments pass through N The connecting components are connected in sequence;

The unit arm section includes first to second piezoelectric vibrators, first to second connection plates, and first to fourth piezoelectric ceramic sheets;

The first and second piezoelectric vibrators both include a metal matrix and first to fourth piezoelectric ceramic sheets;

The metal base includes first to third stepped cylinders, wherein the diameters of the first stepped cylinder and the third stepped cylinder are equal and larger than the diameter of the second stepped cylinder; the two end faces of the second stepped cylinder are respectively the same as the first stepped cylinder. One end face of the cylinder and one end face of the third stepped cylinder are fixedly connected, and the first to third stepped cylinders are coaxial; the center of the second stepped cylindrical column wall is evenly provided with four rectangular patch grooves in the circumferential direction;

The first to fourth piezoelectric ceramic sheets are respectively pasted in the four rectangular patch grooves, and are polarized along the thickness direction. The first and third piezoelectric ceramic sheets are parallel to each other and have the same polarization direction. 2. The fourth piezoelectric ceramic sheets are parallel to each other and have the same polarization direction, and the planes where the first and second piezoelectric ceramic sheets are located are perpendicular to each other;

The first to fourth piezoelectric ceramics are used for inputting external driving signals to make the metal base vibrate;

The first and second connecting plates are arranged in parallel, and both ends of the first and second connecting plates are respectively fixed vertically to the first-order bending vibration nodes of the second stepped cylinders of the first and second piezoelectric vibrators. even;

the connecting assembly includes first to fourth sliding bearing rings, and first to fourth double hook springs;

The first to fourth sliding bearing rings are all annular, and are provided with a first connection hole and a second connection hole whose connecting line passes through the center of the circle; the directions of the spring hooks at both ends of the first to fourth double hook springs are perpendicular to each other;

One ends of the first double hook spring and the second double hook spring are respectively connected with the first connecting hole and the second connecting hole of the first sliding bearing ring, and the other ends are respectively connected with the first connecting hole of the third sliding bearing ring and the fourth sliding bearing ring. The connecting holes are connected; one end of the third double hook spring and the fourth double hook spring are respectively connected with the first connecting hole and the second connecting hole of the second sliding bearing ring, and the other ends are respectively connected with the third sliding bearing ring and the fourth sliding bearing ring. The second connection holes are connected; the planes where the first sliding bearing ring and the second sliding bearing ring are located are parallel to each other, the planes where the third sliding bearing ring and the fourth sliding bearing ring are located are parallel to each other, and the first sliding bearing ring and the third sliding bearing ring are parallel to each other. The planes are perpendicular to each other;

When the unit arm segment and its adjacent unit arm segment are connected through the connecting assembly, the first and second sliding bearing rings of the connecting assembly are sleeved on the second stepped cylinder of the second piezoelectric vibrator metal base of the unit arm segment for clearance fit, The third and fourth sliding bearing rings of the connecting assembly are clearance-fitted on the second stepped cylinder of the metal base of the first piezoelectric vibrator of the adjacent unit arm section, so that the first and fourth sections of the second piezoelectric vibrator metal base of the unit arm section are in clearance fit. The three-step cylinder and the first and third step cylinders of the metal base of the first piezoelectric vibrator of the adjacent unit arm section are orthogonally offset.

As a further optimized solution of a patch-type piezoelectric-driven two-degree-of-freedom fully open underwater manipulator of the present invention, the first to fourth piezoelectric ceramic sheets are glued and pasted on the second stepped cylinder by epoxy resin. Four rectangular patch slots, and insulated with waterproof glue.

As a further optimization scheme of the patch piezoelectric driven two-degree-of-freedom fully open underwater manipulator of the present invention, the metal base is provided with a through hole along its axis, and the first stepped cylinder is away from one end of the second stepped cylinder, One end of the third stepped cylinder away from the second stepped cylinder is provided with a circular groove coaxial with the second stepped cylinder.

As a further optimization scheme of the patch piezoelectric driven two-degree-of-freedom fully open underwater manipulator of the present invention, the first and second connecting plates are provided with symmetrical circular mounting holes at both ends, and a rectangular hole in the middle. ;

Both ends of the first and second connecting plates are respectively connected with the second stepped cylinders of the first and second piezoelectric vibrators through interference fit through their mounting holes.

The invention also discloses a unit arm section driving method of the patch type piezoelectric driving two-degree-of-freedom fully open underwater manipulator, comprising the following steps:

A first harmonic drive signal is applied to the first and third piezoelectric ceramic sheets of the unit arm segment, and the same frequency as the first harmonic drive signal is applied to the second and fourth piezoelectric ceramic sheets of the unit arm segment and has the same frequency as the first harmonic drive signal. The second simple harmonic drive signal with a π/2 time phase difference excites the first and second piezoelectric vibrators in the first-order bending vibration modes that are orthogonal to each other in time and space, so that the points at both ends of the metal substrate generate microscopic vibrations. Amplitude elliptical motion, the first and second piezoelectric vibrators of adjacent unit arm sections provide support to generate friction force, and through friction, a driving force is generated, so that the unit arm section rotates relative to its adjacent unit arm sections.

Compared with the prior art, the present invention adopts the above technical scheme, and has the following technical effects:

1. Compared with the traditional electromagnetic and hydraulic drive manipulators, it has a simple structure, light weight, no need for gear reduction and other mechanisms, easy to seal, easy to achieve micro-miniaturization, low operating noise, easy to achieve low speed and large torque, free from electromagnetic interference, and can be powered off Self-locking;

2. Compared with other piezoelectrically actuated manipulators, since the piezoelectric vibrator is an axisymmetric structure, the first-order bending vibration in its two orthogonal directions has a natural two-phase modal frequency consistency, and there is no need to perform different phases. The consistent adjustment of the modal coupling frequency of the modes reduces the restrictions on the design size and shape of the manipulator, and it is easier to realize serialization and modular design. It has strong engineering applicability and has important application prospects.

Description of drawings

Figure 1 is a schematic structural diagram of a patch type piezoelectric driven two-degree-of-freedom underwater manipulator;

Fig. 2 is the structural schematic diagram of the unit arm section;

Fig. 3 is the structural representation of metal matrix;

Fig. 4 is the structural representation of the first connecting plate;

Fig. 5 is the structural representation of connection assembly;

6 is a schematic diagram of applied voltage signals of the first to fourth piezoelectric ceramic sheets;

7 is a schematic diagram of the first-order bending vibration vibration mode of the second piezoelectric vibrator along the Z axis in the ZOX plane;

FIG. 8 is a schematic diagram of the first-order bending vibration vibration mode of the second piezoelectric vibrator along the Z axis in the ZOY plane.

In the figure, 1-first unit arm section, 2-connection assembly, 3-first piezoelectric vibrator, 4-first connection plate, 5-second piezoelectric vibrator, 6-second connection plate, 7-first Stepped Cylinder, 8-Second Stepped Cylinder, 9-Third Stepped Cylinder, 10-Rectangular Patch Slot, 11-Installation Round Hole on the First Connecting Plate, 12-Rectangular Hole on the First Connecting Plate, 13-No. A sliding bearing ring sleeve, 14- the second sliding bearing ring sleeve, 15- the third sliding bearing ring sleeve, 16- the fourth sliding bearing ring sleeve, 17- the first double hook spring, 18- the second double hook spring, 19- the first Three double-hook springs, 20-fourth double-hook springs.

Detailed ways

Below in conjunction with accompanying drawing, the technical scheme of the present invention is described in further detail:

The present invention may be embodied in many different forms and should not be considered limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.

As shown in FIG. 1 , the present invention discloses a patch-type piezoelectric driven two-degree-of-freedom underwater manipulator, which includes several N+1 unit arm segments and N connecting components, where N is a natural number greater than or equal to 1, The N+1 unit arm segments are connected in sequence through N connection components.

As shown in FIG. 2 , the unit arm section includes first to second piezoelectric vibrators, first to second connection plates, and first to fourth piezoelectric ceramic sheets.

The first and second piezoelectric vibrators both include a metal matrix and first to fourth piezoelectric ceramic sheets;

As shown in FIG. 3 , the metal base includes first to third stepped cylinders, wherein the diameters of the first stepped cylinder and the third stepped cylinder are equal and larger than the diameter of the second stepped cylinder; The end faces are respectively fixed with one end face of the first stepped cylinder and one end face of the third stepped cylinder, and the first to third stepped cylinders are coaxial; slot.

The metal base body is provided with a through hole along its axis, and the end of the first stepped cylinder away from the second stepped cylinder and the end of the third stepped cylinder away from the second stepped cylinder are provided with a circular concave coaxial with the second stepped cylinder. groove.

The first to fourth piezoelectric ceramic sheets are respectively pasted in the four rectangular patch grooves, and are polarized along the thickness direction. The first and third piezoelectric ceramic sheets are parallel to each other and have the same polarization direction. 2. The fourth piezoelectric ceramic sheets are parallel to each other and have the same polarization direction, and the planes where the first and second piezoelectric ceramic sheets are located are perpendicular to each other; the first to fourth piezoelectric ceramic sheets are used to input external driving signals to make the metal substrate vibrate .

The first and second connecting plates are arranged in parallel, and both ends of the first and second connecting plates are respectively fixed vertically to the first-order bending vibration nodes of the second stepped cylinders of the first and second piezoelectric vibrators. As shown in Figure 4, the first and second connecting plates are provided with symmetrical mounting circular holes at both ends, and a rectangular hole is arranged in the middle; both ends of the first and second connecting plates pass through the The installation round hole is connected with the second stepped cylinder of the first and second piezoelectric vibrators by interference fit.

As shown in FIG. 5 , the connecting assembly includes first to fourth sliding bearing rings and first to fourth double hook springs;

The first to fourth sliding bearing rings are all annular, and are provided with a first connection hole and a second connection hole whose connecting line passes through the center of the circle; the directions of the spring hooks at both ends of the first to fourth double hook springs are perpendicular to each other;

One ends of the first double hook spring and the second double hook spring are respectively connected with the first connecting hole and the second connecting hole of the first sliding bearing ring, and the other ends are respectively connected with the first connecting hole of the third sliding bearing ring and the fourth sliding bearing ring. The connecting holes are connected; one end of the third double hook spring and the fourth double hook spring are respectively connected with the first connecting hole and the second connecting hole of the second sliding bearing ring, and the other ends are respectively connected with the third sliding bearing ring and the fourth sliding bearing ring. The second connection holes are connected; the planes where the first sliding bearing ring and the second sliding bearing ring are located are parallel to each other, the planes where the third sliding bearing ring and the fourth sliding bearing ring are located are parallel to each other, and the first sliding bearing ring and the third sliding bearing ring are parallel to each other. The planes are perpendicular to each other.

When the unit arm segment and its adjacent unit arm segment are connected through the connecting assembly, the first and second sliding bearing rings of the connecting assembly are sleeved on the second stepped cylinder of the second piezoelectric vibrator metal base of the unit arm segment for clearance fit, The third and fourth sliding bearing rings of the connecting assembly are clearance-fitted on the second stepped cylinder of the metal base of the first piezoelectric vibrator of the adjacent unit arm section, so that the first and fourth sections of the second piezoelectric vibrator metal base of the unit arm section are in clearance fit. The three-step cylinder and the first and third step cylinders of the metal base of the first piezoelectric vibrator of the adjacent unit arm section are orthogonally offset.

The first to fourth piezoelectric ceramic sheets are bonded and pasted in the four rectangular patch grooves of the second stepped cylinder by epoxy resin glue, and are insulated with waterproof glue.

The invention also discloses a unit arm section driving method of the patch type piezoelectric driving two-degree-of-freedom fully open underwater manipulator, comprising the following steps:

As shown in FIG. 6 , the first harmonic drive signal is applied to the first and third piezoelectric ceramic sheets of the unit arm segment, and the first harmonic drive signal is applied to the second and fourth piezoelectric ceramic sheets of the unit arm segment. The second simple harmonic drive signal with the same frequency as the drive signal and with a π/2 time phase difference excites the first-order bending vibration modes of the first and second piezoelectric vibrators that are orthogonal to each other in time and space, as shown in Figure 7, As shown in Fig. 8, slight elliptical motion is generated at each point at both ends of the metal substrate, and the first and second piezoelectric vibrators of the adjacent unit arm segments provide support to generate frictional force, and through frictional action, a driving force is generated, so that the unit The boom section rotates relative to its adjacent unit boom section.

When working, the drive signal can be applied to the piezoelectric vibrators of the adjacent unit arm segments respectively, and the unit arm segment can be rotated around the piezoelectric vibrator of the adjacent unit arm segment in the circumferential direction and the piezoelectric vibrator of the unit arm segment around itself can be respectively realized. Rotation of the axis. Since the unit arm section and its adjacent unit arm sections are orthogonal in space, applying driving signals to the piezoelectric vibrators corresponding to the two unit arm sections can realize two-degree-of-freedom rotation of the two arm sections in the orthogonal plane.

The invention proposes a patch-type piezoelectric driven two-degree-of-freedom underwater manipulator and a drive method thereof. Compared with the traditional underwater work manipulator, the invention has a simple structure, light weight, easy miniaturization and sealing treatment, and is immune to electromagnetic Interference, can be self-locking when power off, because the piezoelectric vibrator is an axisymmetric structure, the two-phase modal frequency consistency of the same-order bending vibration in two orthogonal directions is used, and there is no need to perform the modal coupling frequency consistency of different phase modes. It reduces the restrictions on the design size and shape of the manipulator, makes it easier to realize serialization and modular design, and shortens the design cycle. It has important application prospects for the working manipulator of underwater micro-miniature robots.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should also be understood that terms such as those defined in the general dictionary should be understood to have meanings consistent with their meanings in the context of the prior art and, unless defined as herein, are not to be taken in an idealized or overly formal sense. explain.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (5)

1. A patch-type piezoelectric driven two-degree-of-freedom underwater manipulator, characterized in that it comprises several N+1 unit arm segments and N connecting components, where N is a natural number greater than or equal to 1, and the N+1 The unit boom sections are connected in sequence through N connection components; The unit arm section includes first to second piezoelectric vibrators, first to second connection plates, and first to fourth piezoelectric ceramic sheets; The first and second piezoelectric vibrators both include a metal matrix and first to fourth piezoelectric ceramic sheets; The metal base includes first to third stepped cylinders, wherein the diameters of the first stepped cylinder and the third stepped cylinder are equal and larger than the diameter of the second stepped cylinder; the two end faces of the second stepped cylinder are respectively the same as the first stepped cylinder. One end face of the cylinder and one end face of the third stepped cylinder are fixedly connected, and the first to third stepped cylinders are coaxial; the center of the second stepped cylindrical column wall is evenly provided with four rectangular patch grooves in the circumferential direction; The first to fourth piezoelectric ceramic sheets are respectively pasted in the four rectangular patch grooves, and are polarized along the thickness direction. The first and third piezoelectric ceramic sheets are parallel to each other and have the same polarization direction. 2. The fourth piezoelectric ceramic sheets are parallel to each other and have the same polarization direction, and the planes where the first and second piezoelectric ceramic sheets are located are perpendicular to each other; The first to fourth piezoelectric ceramics are used for inputting external driving signals to make the metal base vibrate; The first and second connecting plates are arranged in parallel, and both ends of the first and second connecting plates are respectively fixed vertically to the first-order bending vibration nodes of the second stepped cylinders of the first and second piezoelectric vibrators. even; the connecting assembly includes first to fourth sliding bearing rings, and first to fourth double hook springs; The first to fourth sliding bearing rings are all annular, and are provided with a first connection hole and a second connection hole whose connecting line passes through the center of the circle; the directions of the spring hooks at both ends of the first to fourth double hook springs are perpendicular to each other; One ends of the first double hook spring and the second double hook spring are respectively connected with the first connecting hole and the second connecting hole of the first sliding bearing ring, and the other ends are respectively connected with the first connecting hole of the third sliding bearing ring and the fourth sliding bearing ring. The connecting holes are connected; one end of the third double hook spring and the fourth double hook spring are respectively connected with the first connecting hole and the second connecting hole of the second sliding bearing ring, and the other ends are respectively connected with the third sliding bearing ring and the fourth sliding bearing ring. The second connecting holes are connected; the planes where the first sliding bearing ring and the second sliding bearing ring are located are parallel to each other, the planes where the third sliding bearing ring and the fourth sliding bearing ring are located are parallel to each other, and the first sliding bearing ring and the third sliding bearing ring are parallel to each other. The planes are perpendicular to each other; When the unit arm segment and its adjacent unit arm segment are connected through the connecting assembly, the first and second sliding bearing rings of the connecting assembly are sleeved on the second stepped cylinder of the second piezoelectric vibrator metal base of the unit arm segment for clearance fit, The third and fourth sliding bearing rings of the connecting assembly are clearance-fitted on the second stepped cylinder of the metal base of the first piezoelectric vibrator of the adjacent unit arm section, so that the first and fourth sections of the second piezoelectric vibrator metal base of the unit arm section are in clearance fit. The three-step cylinder and the first and third step cylinders of the metal base of the first piezoelectric vibrator of the adjacent unit arm section are orthogonally offset. 2 . The patch-type piezoelectric-driven two-degree-of-freedom fully open underwater manipulator according to claim 1 , wherein the first to fourth piezoelectric ceramic sheets are adhered to the first to fourth piezoelectric ceramic sheets by epoxy resin adhesive bonding. 3 . The four rectangular patch grooves of the two-step cylinder are insulated with waterproof glue. 3. The patch-type piezoelectric-driven two-degree-of-freedom fully open underwater manipulator according to claim 1, wherein the metal base is provided with a through hole along its axis, and the first stepped cylinder is far away from the second stepped One end of the cylinder and one end of the third stepped cylinder away from the second stepped cylinder are provided with a circular groove coaxial with the second stepped cylinder. 4. The patch-type piezoelectric drive two-degree-of-freedom fully open underwater manipulator according to claim 1, wherein the first and second connecting plates are provided with symmetrical mounting holes at both ends, and the middle with rectangular holes; Both ends of the first and second connecting plates are respectively connected with the second stepped cylinders of the first and second piezoelectric vibrators through interference fit through their mounting holes. 5. The unit arm section driving method based on the patch type piezoelectric driving two-degree-of-freedom fully open underwater manipulator arm according to claim 1, is characterized in that, comprises the following steps: A first harmonic drive signal is applied to the first and third piezoelectric ceramic sheets of the unit arm segment, and the same frequency as the first harmonic drive signal is applied to the second and fourth piezoelectric ceramic sheets of the unit arm segment and has the same frequency as the first harmonic drive signal. The second simple harmonic drive signal with a π/2 time phase difference excites the first and second piezoelectric vibrators in the first-order bending vibration modes that are orthogonal to each other in time and space, so that the points at both ends of the metal substrate generate microscopic vibrations. Amplitude elliptical motion, the first and second piezoelectric vibrators of adjacent unit arm sections provide support to generate friction force, and through friction, a driving force is generated, so that the unit arm section rotates relative to its adjacent unit arm sections.

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